US Bridges

I-26 over S.C 7/COSGROVE Ave

Fair

Charleston County, South Carolina · In N Charleston · Structure no. 000000000004268

Built
1964
61 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
469 ft
1 main span
Daily traffic
93,200
2023 count
Owner
State
State Highway Agency

About this bridge

I-26 over S.C 7/COSGROVE Ave is a steel stringer/multi-beam or girder carrying I-26 over S.C 7/COSGROVE Ave in Charleston County, South Carolina. It was built in 1964, so it is 61 years old, older than the South Carolina average of 48 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 93,200 vehicles a day, roughly 5% of them trucks, projected to reach 143,528 by 2043. The structure is 469 ft (143 m) long and 117 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-26
CrossesS.C 7/COSGROVE Ave
LocationIn N Charleston
RouteInterstate 26
CountyCharleston County
StateSouth Carolina
Coordinates32.84354, -79.98058
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating70 US tons
Inventory rating37.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+8 approach)
Design loadHS 20
Structure length469 ft (143 m)
Longest span93 ft (28.3 m)
Deck width117 ft (35.8 m)
Roadway width112 ft (34.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic93,200 (2023)
Projected traffic143,528 by 2043
Trucks5%
Lanes on structure8
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$2.2 million (2024 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-26 over S.C 7/COSGROVE Ave built?

It was built in 1964, making it 61 years old in 2025.

What condition is I-26 over S.C 7/COSGROVE Ave in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in August 2024.

How much traffic does I-26 over S.C 7/COSGROVE Ave carry?

About 93,200 vehicles per day (2023 count), of which roughly 5% are trucks.

How long is I-26 over S.C 7/COSGROVE Ave?

The structure is 469 ft (143 m) long with a longest span of 93 ft (28.3 m) and a deck 117 ft wide.

Who owns I-26 over S.C 7/COSGROVE Ave?

It is owned by the State Highway Agency.